I am using an OPA335 as a direct coupled Unity Gain Amplifier fed from a very small DC signal sensor and outputting through a cable to a connector. The purpose of the amplifer being to lower the output impedance and minimise noise pickup on the cable.
Witth zero input It seems to work very well when first switched on (outputting zero), but after about a minute gradually creeps up.
Is the problem caused by being directly coupled without resistive buffers?